speculations _à priori_, founded on general and often inaccurate
observations of natural occurrences. Yet their acuteness was such, that
some of their speculations as to the constituent properties of matter
coincide in a wonderful degree with those which now prevail among modern
philosophers. It is not easy to define what chemistry is in a few words,
but it may be described as the science which has for its object the
investigation of all elementary bodies which exist in the universe, with
the view of determining their composition and properties. It also seeks
to detect the laws which regulate their mutual relations, and the
proportions in which these elements will combine together to form the
compounds which constitute the animal, vegetable, and mineral kingdoms,
as well as the properties of these various compounds. The ancients
admitted only four elements--earth, air, fire, and water. Chemists now
far exceed this number, and seek to show what these elements are
composed of by analysing them into the various gases, solids, and
liquids.

Astronomy is the most ancient of all the sciences. The Chaldeans, the
Egyptians, the Chinese, the Hindoos, Gauls, and Peruvians, each regarded
themselves as the inventors of astronomy, an honour which Josephus
deprives them of by ascribing it to the antediluvian patriarchs. From
the few facts to be gleaned out of the vague accounts by ancient authors
regarding the Chaldeans, it may be inferred that their boasted knowledge
of this science was confined to observations of the simplest kind,
unassisted by any instruments whatever. The Egyptians, again, though
anciently considered the rivals of the Chaldeans in the cultivation of
this science, have yet left behind them still fewer records of their
labours, though it is so far certain that their astronomical knowledge
was even greater than that of the Chaldeans. The Phoenicians seem to
have excelled in the art of navigation, and would no doubt direct their